And that fact makes it essential that both sides grow up and address the nation's – and the world's — most pressing problems like adults.

"The Democrats are being very negative and it's time for them to accept the Trump presidency," Dershowitz said Thursday to Newsmax TV's JD Hayworth.

"But let's just go back eight years and remember how the Republicans treated the Obama presidency — including Donald Trump who said it was an illegitimate presidency, he shouldn't have been allowed to run.

"So I think we're seeing it on both sides and I think the time has come for grownups, for adults in the room to say enough is enough."

Dershowitz said the nation should tell lawmakers, "let's get to policy, let's get to trying to change the tax code in a way that helps all Americans' healthcare, that helps all Americans. Let's deal with North Korea, let's deal with Syria and let's stop this extremism."

"What I worry about is all over the world we're seeing the left move further to the left and the right move further to the right," Dershowitz, a retired Harvard law professor, told Hayworth.

"We're not having conversations like we're having the two of us — a centrist liberal Democrat and a centrist conservative Republican having rationale discourse about the future of America and the future of the world. That's disappearing.

"On college campuses, our future leaders, are not learning how to have conversations. They're learning how to scream at each other. They're learning how to demand safe spaces. They're learning how to become the kind of leaders that are the last thing in the world we need."